Aqueous textile coating composition containing a perfluoroalkyl acrylate and a methyl pyridinium halide



35%2542 Patented July 3, 1962 3,042,642 AQUEOUS TEXTILE COATING COMPOSITION CONTAINING A PERFLUOROALKYL ACRY- LATE AND A METHYL PYRIDINIUM HALIDE Carlo G. De Marco, Cochituate, and Gil M. Dias, River, Mass., assignors to the United States of America as represented by the Secretary of the Army N Drawing. Filed Oct. 6, 1959, Ser. No. 844,830 9 Claims. (Cl. 260-295) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein, if patented, may be manufactured and used by or for the Government for governmental purposes, without the payment to us of any royalty thereon.

This invention relates to the production of launderable Water-resistant and oil-resistant textiles, and more particularly to the application to cotton and other textiles of a novel liquid composition of a mixture of chemical textile-treating agents. We have discovered that our treatment confers a much greater measure of water resistance and oil resistance to such fabrics than could be achieved by the individual applications of any of the components of this liquid mixture, and particularly that the treated textiles possess an unprecedented permanence in the retention of these desirable properties even after a large number of repeated launderings.

Numerous attempts have been made in the course of textile research leading to the provisions of improved textiles for military and civilian uses to confer Water resistance and/or oil resistance on fabrics. While water resistance and oil resistance are obviously desirable properties of textiles tested for civilian use, it is even more important that military clothing for use in combat, in motor maintenance and other working conditions be both water-resistant and oil-resistant, and able to retain these properties unchanged after many repeated launderings. Commercial processes have not, up to now, made it possible to produce military clothing having the desired measure and permanence of water resistance and oil resistance.

We have unexpectedly discovered in the course of our research that a combination treatment with a liquid mixture of two types of commercially available textile treating agents confers permanent water resistance and oil resistance on textiles many times in excess of the water resistance and/or oil resistance that either type of textile treating agent is able to confer individually. As stated, the permanency of the treatment after many repeated launderings, conferred by the use of our invention is likewise more than adequate to meet rigid military requirements, which treatment in accordance with the knowledge of the trade, prior to our invention, was not able to provide.

It is accordingly a principal object of our invention to provide a synergistic treatment for cotton and other textile fabrics which renders them permanently water-resistant and/or oil resistant.

Another object of our invention is the use of textiletreating compositions whose active ingredients are commercially available textile-treating agents.

A further object of our invention is a process which can be practiced with regular machinery in use in the textile trade, and which does not necessitate special training for operators.

Another object of our invention is an air-permeable launderable textile fabric possessing superior permanent resistance to water and oil, and suitable for military and civilian clothing, as well as for covers and other industrial-uses, under severe conditions of use.

Other objects and advantages of our invention will become readily apparent from the following description of our invention.

Generally speaking, we accomplish the objects of our invention by treating textiles with a liquid mixture of (a) quaternary long-chain-carrying pyridinium compound, and (b) an organic fluorine compound, namely a polymerizable fluoro alkyl ester of acrylic acid of a Wernertype chromium complex wherein trivalent nuclear chromium coordinated with a saturated perfluoro-monocarboxylic acid.

As will be more fully explained hereinafter, two preferred pyridinium compounds for the practice of our invention are, respectively, octadecyloxymethyl pyridinium chloride (stearoxy methyl pyridinium chloride) and stearamidomethyl pyridiniumchloride. Octadecyloxymethyl pyridinium chloride is a commercially available waterrepellent compound produced e.g., under the designation Norane R. Stearamidomethyl pyridinium chloride is a water-repellent compound produced under the designation Zelan AP. Both compounds have been tried on Army clothing fabrics and were found to offer good initial water resistance properties, which, however, is quickly reduced and then altogether lost after a few launderings; and they confer virtually no oil resistance.

Among commercially available fluorine compounds heretofore tested for use on textiles for military use are fluoroalkyl esters of acrylic acid; these fluoroalkyl esters of acrylic acid are capable of polymerization in situ on the fabric. They offer good initial oil resistance, but insuflicient initial water resistance to meet military requirements and even less water resistance after laundering; moreover, the oil resistance is quickly reduced below the point of military acceptability after a few launderrngs.

In the course of these and other tests, we have made the unexepected and surprising discovery that the foregoing drawbacks can be eliminated and a superior product obtained by treating the textile fabric with a liquid composition being a mixture of a quaternary long-chain radicalcarrying pyridinium compound and of an organic fluorine compound of the general type about to be set forth. The quaternary pyridinium compounds suitable for use in such a composition has the general formula:

R.A.CH2

N-Hal CZH5 wherein R is an aliphatic hydrocarbon radical having at least about 12 carbon atoms, A is selected from O and CONI-I, and Hal is halogen. This pyridinium compound is preferably in aqueous solution. The organic fluorine compound is preferably in emulsion form because of its low water-solubility; it is either a polymerizable fluoroalkyl ester of acrylic acid having at least about 9 fluorine atoms and from about 4 to about 10 carbon atoms in the ester-forming radical, or a Wernertype chromium complex wherein trivalent nuclear chromium is coordinated with a saturated perfluoro-monocarboxylic acid having from about 5 to about 11 carbon atoms in the molecule. The aqueous emulsion of the organic fluorine compound and the aqueous solution of the pyridinium compound are combined in the form of an aqueous dispersion, preferably bulfered.

We have found that a preferred ratio of pyridinium compound to organic fluorine compound is about 2-3 parts by weight of pyridinium compound per 1 part of organic fluorine compound; within the foregoing range an approximately 2:1 ratio is recommended. Acceptable results, in terms of performance, but not as efiective as those obtained within the foregoing range, were also obtained with a ratio of about 1-4.5 parts by weight of pyridinium compound per 1 part of organic fluorine compound; however, oil-resistance is less satisfactory in the 4.5:1 ratio and falls below military performance require .ments above that range. Conversely, water resistance of the treated fabric is not sufficiently effective for military "requirements below a 1:1 ratio of pyridinium compound to organic fluorine compound.

. Reverting now to the quaternary pyridinium compounds for use in the practice of our invention, we prefer chlorides for ready commercial availability, but also contem plate other halides such as bromides and iodides. The long-chain substituent on the pyridinium group is an aliphatic hydrocarbon radical connected to an oxy (--O-) or amido CONH) group, which in turn is joined to the nitrogen atoms of the pyridinium" group by -CH The preferred aliphatic hydrocarbon radical is a saturated hydrocarbon radical having 17 or 18 carbon atoms for reasons of ready commercial availability and reliability of performance of the end product; however, other saturated or unsaturated long-chain aliphatic hydrocarbon radicals of 12 or more carbon atoms, such as dodecyl, tetradecyl, hexadecyl, eicosyl, docosyl, oleyl, are Within the contemplation of our invention.

The polymerizable alkyl esters of acrylic acid for use in our invention in combination with the above-described pyridinium compounds are represented by the. general formula, CHyCI-LCOOR, where R is a perfluorinated alkyl group, the alkyl group having about 4 to carbon atoms. A preferred compound of this type is perfluorobutyl acrylate, of the formula CH :CH.COO.C F

A typical Werner-type chromium coordination complex of a perfluorinated monocarboxylic acid suitable for the practice of our invention in synergistic combination with a pyridinium compound of the class described as C|7F15 0 O J. I H8120! CrHal;

wherein Hal is halogen, e.g., chloro or'fluoro. This isa compound of a trivalent chromium salt and perfluoro octanoic acid formed in accordance with the valence to etfect a dry add-on (weight increase) of solids of from theory of Professor Alfred Werner; according to the Werner theory, atoms may exert auixilary valences as well as principal valences, in which case the auxiliary valences act to hold various groups to the atom which exerts such auxiliary valences, whereby the atom exerting I,

the principal and auxiliary valences becomes the nuclear atom of a complex. The aforementioned graphic formula may be written more generally group is a radical derived fiom a saturated perfluoromonovalent acid having from about 5 to 11 carbon atoms in the molecule.

Ina preferred form of producing the synergistic eifect of our invention, the textile-treating process is carried out by padding onto a textile material a bulfered aqueous dispersion consisting of two parts (solids) of the pyridinium compound to one part organic fluorine compound. The totalsolids content in the treating bath and the application of the dispersion to the textile material are. adjusted 2 to 7 percent based on the dry weight of the textile material. After padding, the treated material is subjected to a non-injurious elevated temperature substantially above room temperature, such as drying between about 200- 300 F. and curing within a temperature range of 250 to 400 F. The fabric is then washed with a wetting agent, neutralized with soda ash, and then rinsed in water and dried.

The following specific examples will further illustrate the practice of our invention, but are not to bedeemed to limit the scope of our invention to any procedural or other details there set forth:

Example I 360 grams of stearamidomethyl pyridinium chloride are dissolved in 1489 grams of water. Separately, 60 grams of sodium acetate crystals are dissolved in 500 grams of water. In each case the Water is maintained at a temperature of 110 to 130 F. The acetate and the stearamidomethyl pyridinium chloridev are then combined and the temperature maintained within the'range stated. A 590 gram nonionic emulsion consisting of 180 grams of a fluoroalkyl ester of acrylic acid such as perfluoro'butyl acrylate, grams of acetone and 325 grams of Water is then added to the stearamidomethyl pyridinium chloridesodium acetate dispersion. The temperature of the final dispersion is maintained between and F.

This dispersion is applied to a 9.0 oz. cotton sateen cloth by means of 2 dips and 2 nips using conventional padding equipment. The fabric is then dried at a temperature of 240 F. for 2 /2 minutes and then cured for 1% minutes at 350 F.

The treated fabric is then 'jig washed for 10 minutes in a solution containing .05 wetting agent and .1% soda ash. The washing temperature is approximately F. After washing, the fabric is dried at a temperature of about 300 F. The increase in fabric weightdue to this application is about 5.0%. A rainroom comparison of this treated material with: (1) the same type of fabric containing a dry add-on of 4.0% (not possible to eficct a higher add-on) of the fluoroalkyl ester of acrylic acid alone and (2) the same type of fabric containing 5.2% dry add-on of the stearamidomethyl pyridinium chloride alone are as follows:

TIME (HOURS) REQUIRED TO FAIL RAIN TEST (SIMULATED RAINFALIJ OF 1.0 INJHR.)

' Pyrldinium Fluoroalkyl Laundertngs Fluoroalkyl Compound Ester Ester Alone Alone Pyridinlum Compound 1 Test terminated at this point.

The launderings were performed in a rotary reversible cylinder washer standardized for use in Quartermaster mobile laundriesJ The following washing procedure was employed with the use of a powdered detergent:

Water Time Temper- Operation Level (min.) ature Supplies (in) (deg. F.) p

Suds 5 5 100 Detergent (6 oz.). 5 5 130 Detergent (3 02.). 5 5 140 Detergent (2 02.). 8 3 140 8 3 120 8 3 100 Sour (2 02.).

Water resistance data obtained-on this material are as follows:

The following details apply to the water resistance test methods used.

a. Spray rating is principally a measure of surface repellency. It is conducted by means of a'funnel connected to a spray nozzle which sprays water onto a test fabric specimen held by a metal hoop at a 45 angle. The percentage of test fabric area still remaining unwetted at the end of a 30-second test generally determines the spray rating; e.g., 100 denotes complete water repellency;

b. Suter hydrostatic is primarily dependent upon fabric structure-but applied repellent does have some effect. This test is carried out by directing water under variable hydrostatic pressure onto the fabric test specimen. The amount of hydrostatic pressure in centimeters needed to penetrate the fabric determines the test rating; thus, a highly water-penetration-resistant fabric will have a high numerical rating.

c. Dynamic absorption is primarily a function of applied finish. As the results show, the material treated with the fluoralkyl ester/pyridinium finish exhibited little change in this property after 15 launderings. This test is carried out in a Water-filled tumble jar. The percentage of Water taken up by the fabric test specimen in terms of the original weight of the specimen determines the rating; thus, a highly water-resistant fabric will have a low numerical rating in this test.

These water resistance tests are in accordance with the methods of Federal Specification CCC-T-19lb. For military performance characteristics the dynamic absorption test is the most important; as shown by the foregoing table, the'amount of water absorbed by a fabric treated in accordance with our invention rises but slightly after 15 launderings (from 23.3 to 24.8), as compared with a two-fold rise in the case of test fabrics treated with either agent alone, thus showing the synergistic effect of the conjoint treatment.

Oil repellency-data obtained on this same material are These tests are as follows:

(1) The oil wicking test measures resistance to liquid travel. A fabric strip is suspended in mineral oil and maximum height of wetting at the end of a 24-hour period is recorded.

(2) The oil penetration test indicates resistance to oil passage. Degree of oil penetration is recorded whena 3 mg. drop of oil is placed on the fabric surface and a l-pound weight is applied on top of the drop for 1 minute.

The absence of oil wicking and penetration after 15 launderings in the fabrics treated in accordance with the present invention is evidence of the synergistic efiect of our contemplated treatment. Analogous protection is afforded against other organic base liquids, such as motor oil, grease, vegetable oils and animal oils.

Example'll Example I was repeated, except'that octadecyloxy methyl pyridinium chloride (stearoxymethyl pyridinium chloride) was substituted for steararnidomethyl pyri dinium chloride. Rainroom values are as follows:

TILIE '(HOURS) REQUIRED TO FAIL RAIN TEST (SIIWULATED RAINFALL OF 1.0 INJHR.)

V Pyridinium V Fl'uor'oalk'yl' Launderings Fluoroalkyl Compound Ester Ester Alone Alone Pyridinium Compound 1 Test terminated at this point.

Oil repellency data obtained on this same material are listed below:

Water resistance data determined in accordance'with test methods of Federal Specification CCC-T-191-b were as follows:

. Fluoro Fluoro- Pyridinalkyl alkyl ium Ester Ester Compound Pyridin- Alone ne ium Compound Spray Rating (Method 5526):

Initially 100 After 15 launderings 0 70 80 Su(ter ])5[ydrostatic (Method 5514) Initially 39. 3 46. 5 50. 5 After 151aunderings 17. 4 23. 4 31. 8 Dynamic Absorption (Percent) (Method 5500):

Initially 31. 2 25. 4 24. 8 After 15 launderings 59. 5 52. 6 28. 5

Example 111 Example IV In another test, a cationic emulsion of perfiuoro butyl acrylate was substituted for the non-ionic emulsion of Example I. The same result was obtained as in Example 1.

Our invention may also be applied to natural, synthetic or blended fabrics, either unfinished or previously finished with a crease-resistant and/ or fire-retardant finish.

. ogists having ordinary experience.

a and modifications within the scope of our invention will A highly desirable property of a clothing textile is air permeability. Ourtreatment has no adverse efiect on air permeability of the fabric.

It will thus be seen that we have provided a synergistic treatment for rendering natural and synthetic textiles water-resistant and oil-resistant, withparticularly superior performance results after many repeated launderings. While we have described several practical examples of the practicerof our invention in terms of application to cotton and nylon fabrics, it will be understood that it is equallyapplicable to other natural and synthetic fabrics, either blended or unblended, such as wool, silk, cellulose acetate, rayon (Viscose), acrylonitr-ile polymers and copolymers, etc., and blends of the foregoing. Likewise, while the specific examples of the foregoing specification describe certain commercially available textile-treating agents in synergistic'conrbination, as well as preferred conditions for their use, it will be clear to the expert that the results of our invention may be achieved by suitable substitutions andalterations within the skill of technol- Still other changes also readily occur to the expert and are deemed to be whereinR is an aliphaticrnonovalent .hydrocarbon radi 'cal having fiomlZ to 22 carbon atoms, A is selected encompassed within the scope of our invention, which a we now proceed to define by the appended claims.

We claim: V

1. A liquid composition for rendering a textile permanently water-resistant and oil-resistant even after repeated launderings, comprising an aqueous dispersion of an aque- .ous solution of a methyl pyridinium halide having the general formula:

I B.A.CH2

N-Hal s s wherein R is an aliphatic monovalent hydrocarbon radical having from 12 to 22' carbon atoms, A is selected from O-- and CONH-, and Hal is halogen, and

' of a water emulsion of a perfluoroalkyl acrylate having from 4 to 10 carbon atoms in the alkyl' group; said pyridinium halide being present in a ratio of from about 1 to about 4.5 parts by weight per 1 part of said perfiuoroalkyl acrylate.

2. A liquid composition for rendering a textile perfrom -O- and -CONH, and Hal is halogen, and of a water emulsion of a perfl'uoroalkylacrylate'having from,4 to 10 carbon atoms in the alkyl group; said .pyridinium halide being present in a ratio of from about 2 to about 3 parts by weight per 1 part of said perfluoroalkyl acrylate. a

3. A liquid composition for rendering a textile permanently water-resistant and oil-resistant even after repeated launderings, comprising an aqueous dispersion of an aqueous solution of a stearoxymethylpyridinium halide and of a water emulsion of perfluorobutyl acrylate; said stearoxymethyl pyridinium halide being present ina ratio of from about 1 to about 4.5 parts by weight per 1 part of said perfluorobutyl-acrylate.

' 4. A liquid composition for rendering a textile permanently water-resistant and oil-resistant even after repeated launderings, comprising an aqueous dispersion of an aqueous solution of a stearamidomethyl pyridinium halide and of a water emulsion of perfluorobutyl acrylate; said stearamidomethyl pyridinium halide being present in a ratio of from about 1 to about 4.5 parts by weight per 1 part of said perfluorobutyl acrylate.

5. A composition according to claim 3 wherein said halide is a chloride, and is present in a ratio of from about 2 to about 3' parts by weight per 1 part of said perfluorobutyl acrylate. 1

6. A composition according to claim 4 wherein said halide is a chloride, and is present in a ratio of. from about 2 to about 3 parts by weight per 1 part of said perfluorobutyl acrylate.

7. The composition according to claim 1, wherein the weight ratio of said pyridinium compound and of said perfluoroalkyl acrylate is about 2:1. I

8. The composition according to claim 1, wherein said solution phase also contains a minor amount of a. buttering agent.

9. The composition according to claim 1, wherein said buffering agent is sodium acetate.

References Cited in the file of this patent UNITED STATES PATENTS 2,293,844 Maxwell Aug. 25, 1942 2,407,989 Luckhaupt Sept. 24, 1946 2,868,752 Frazier et al Jan. 13, 1959 2,889,297. Brandner et a1. June 2, 1959 FOREIGN PATENTS 477,991 Great Britain Jan IO, 1938 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,042,642 July 3, 1962 Carlo G. De Marco et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 40, for "compounds" read compound column 3, ,line 32, for "as" read is line 45, for "auixilary" read auxiliary column 5, in the table at the bottom of the column, column 1, line 1 thereof, for "hight" read height column 8, list of references cited, under "UNITED STATES PATENTS", add the following;

2,803,615 Ahlbrecht et a1. Aug. 20, 1957 Signed and sealed this 30th day of October 1962.

I SEA L) Attest:

ERNEST w. SWIDER DAVID LADD testing Officer Commissioner of Patents 

1. A LIQUID COMPOSITION FOR RENDERING A TEXTILE PERMANENTLY WATER-RESISTANT AND OIL-RESISTANT EVEN OFTER REPEATED LAUNDERING, COMPRISING AN AQUEOUS DISPERSION OF AN AQUEOUS SOLUTION OF A METHYL PYRIDINUM HALIDE HAVING THE GENERAL FORMULA: 